The ZI20A from Mitsubishi Heavy Industries is an internally toothed ring gear grinding machine capable of high-speed and precision with low noise operation. The grinding speed, or sliding velocity, is four times faster than that oaf conventional grinding due in part to MHI's barrel-shaped multi-threaded grinding wheel made of cubic boron nitride (cBN) that attaches to the main spindle.

Longer grinding tool life is one benefit along with a 1/6-reduction in grinding tool cost per workpiece, which is comparable to the cost of preheat processing. The machine also features a synchronous control technology that produces high-speed grinding through fast spindle rotations-15,000 rpm for the main spindle that rotates the grinding wheel and 6,000 rpm for the workpiece spindle.